1. Field of the Invention
The present general inventive concept relates to an auto white balance (AWB) method and an image photographing apparatus using the same, and more particularly, to an AWB method which is efficient for a high definition image and an image photographing apparatus using the same.
2. Description of the Related Art
An image photographing apparatus records, on a recording medium, an image generated by picking up a subject. Examples of an image photographing apparatus are a digital camera and a digital camcorder. For more natural color reproduction, an image photographing apparatus performs an auto white balance (AWB) of the pick-up image and then records the image.
Generally, An AWB method is performed by integrating color difference by using color difference signals of a pick-up image, and adjusting a gain for each color signal based on the calculated integration of the color difference. The pick-up image 10 is divided into four (4) windows {circle around (1)}, {circle around (2)}, {circle around (3)} and {circle around (4)}, as illustrated in FIG. 1, and the color difference integration is calculated with respect to each window.
The AWB performed by the above-described AWB method is suitable for an image of standard definition (SD) but not suitable for an image of high definition (HD). In an HD image, since the size of a pick-up image is very big, the extent of calculation required for the integration of color difference significantly increases.
Specifically, when the AWB is performed by picking up an image in a high speed mode, the number of images being picked-up per unit hour is greater than in a normal mode, and it takes long time to transmit data required for performing the AWB. Furthermore, the extent of calculation for the integration of color difference increases.